For example, as disclosed in JP1999-294264A, there are engines for vehicles provided with an EGR (Exhaust Gas Recirculation) device which recirculates a portion of exhaust gas to an intake passage for reduction in generation of nitrogen oxide (NOx) and pumping loss during intake. JP1999-294264A particularly discloses a structure in which an EGR passage is connected to some of a plurality of independent exhaust passage parts (i.e., independent exhaust pipes) connected to respective cylinders of an engine body.
JP2000-265905A discloses an engine for a vehicle, in which a plurality of independent exhaust passage parts (i.e., exhaust ports), and a collective exhaust passage part (i.e., port collecting part), which collects the plurality of independent exhaust passage parts, are formed in a cylinder head. In this engine, the plurality of independent exhaust passage parts and the collective exhaust passage part are provided inside the cylinder head, and an exhaust pipe is connected to an opening of the collective exhaust passage part which is formed in a side surface part of the cylinder head.
Meanwhile, if the structure of JP1999-294264A is incorporated into the structure of JP2000-265905A, an installation location of an exhaust gas temperature sensor may become a challenge. That is, in the engine which adopts the EGR device, although precise detection of the temperature of exhaust gas is important in terms of, for example, NOx reduction and intake charging efficiency, it is not realistic to install the exhaust gas temperature sensor inside the cylinder head, if maintainability is considered.